1. Field of the Invention
Embodiments of the invention relate to modulation. More specifically, embodiments of the invention relate to an improved encoding density modulation scheme.
2. Description of the Related Art
Various forms of modulation have long been used to encode data with greater efficiency so that more data can be transmitted during a particular time period over a transmission medium. Combinations of various modulation techniques such as, pulse width modulation, amplitude modulation and rise time modulation have been employed to improve the encoding density of modulation schemes. See for example, application entitled “Symbol-Based Signaling For An Electromagnetically-Coupled Bus System,” Ser. No. 09/714,244, now U.S. Pat. No. 6,697,420. However, such schemes typically employ a fixed base pulse residing in a fixed location within the symbol period. This can have a significant limiting effect on the possible modulation symbols available and therefore the modulation gain achievable.